Abstract: A method and a system are disclosed for obtaining the dynamic network state of mobile subscribers, such as subscriber location, presence or other state information. This information, which may be distributed within various core mobile network elements, is obtained via a differentiated network service gateway (DNSG) that interfaces with the mobile network elements in a manner that accommodates the network's operator enforced controls and limitations. The DNSG implements service level agreements (SLAs) that support differentiated quality-of-service (QoS) in terms of accessing the dynamic network state of the mobile subscribers. The consumers (DNSG clients) of the dynamic network state information may include applications that provide communication and transactional services to mobile subscribers based on their network state, and the mobile subscribers themselves.